Cellular structure



2, 1937. J. PAVLECKA CELLULAR STRUCTURE Filed Aug. 19, 1955 PatentedNov. 2, 1937 UNITED STATES PATENT OFFIZCE 26 Claims.

My present invention relates to a structure comprising sheet materialand linear members in a novel combination. 7

Among the objects of my invention is, first, to provide an inexpensive,light and strong construction for such purposes as walls, floors, wingsof aircraft, and girders.

A further object is to devise a closed structure which can be assembledeasily with a minimum of riveting. V 4

Another object is to devise a structure of great strength and leastweight in which pre-fabflcated spars of sheet material cooperate withlinear stress members in load carrying.

A still further object is toprovide a retaining structure, such as awall in a house, which is built up of a number of individual boxelements of sheet material with linear insulating members confinedbetween the elements.

These and other objects and aims of my -invention are materialized, in ageneral way, by producing a number of individual tubular cells or sparsof sheet material, all of them being alike if the resulting structure isto be symmetrical about at least one plane; or, they may be of diversshapes and varyingsizes if the structure is to be irregular in contourwherein each cell or spar occupies a predetermined position. The sparsare preferably fabricated with flanged perforations in their sides forlightness and increased stiifness, and furthermore, for accessibile ityof the interior in riveting the seam of the spars and assembling theminto the structure in the manner disclosed hereinfurther.

The spars are integrated into unity by being lined up alongside oneanother so that their side Webs will either abut on or will confronteach other at a close distance, and between spars so disposed areconfined or wedged linear members, or stringers, or struts or fillerstrips, as the case may be, preferably in such a manner that the sparswill clinch the linear members between them directly at the exterior ofthe structure whereby the members will function as spacers be tweenthespars and will provide a portion of the exterior surface of thestructure between them.

The manner of retaining the spars and the linear members in entity maybe varied, to suit individual preference, the most expedient method,though not the only one here proposed. being to rivet the spars togetherwith the rivets passing through and retaining the linear members in-,between them.

The principle of integrating stressed bodies of a plurality of tubularspars viii- Q linear stress or the structure. V e 7 this structureinclude the shape of the spars 5 insvlatieg emb r c n ne e w en. the nthe manner above disclosed, yields itself to a considerable variety ofmodifications emin ets r ain. mpe w h w n w be described with referenceto the drawing forming an inte :ral part of this specification. In, the

drawing,

Fig. 1 represents a'transverse cross section through a structure ofuniform depth and comprising generally rectangular spars 'with linear mbr clamped e wee t e r o ers.

Fi i imila ossect on, rou h a Structure e 9 r an ular ars o s osed toone anoth er that they form sockets between tween then in a manneranalegous to that of Fig. l.

4 esen s see, of he. linear members a the shoulders of the sparsengaging same as well as the rivets" tying the, spars together, shown onn i d' ea e; ap ain n to the t u ur of Fig. l2 I "Figs. 5 and 6 areapproximately full-,si zesec-v tional reproductions, Oi the linearmembers and their vicinity of Figs. 3 and 2, respectively, and

disclose exemplary methods of retaining the linear members in place andthe spars in unit The same numerals in difierent figures desige nateidenticalcomponent parts.

All of the struetures shown in the dravvingare.

distinguished by certain fatures generic to all e of them, ar d byothers characterizing each ndi vidual e e i e b t, qua y W a p icable sthe rest of them.

The genericfeatures distinguishing the struc tureof Fig. l reside'iinthe individually fashioned tubular spars or elements 5 to}, andin thelinear members 9 confined between them in such a.

manner that the sparshave a retaining and restraining hold on them, thusreinforcing them against failure under strain, and being. in turn,

reinforced by thejmembers by virtue of the latters strategic location atthe exteri r surfacesof The individual characteristics of and provides.portion of the exteriorsurface of th .5trnct r The spars 5 to 8, allalike, have each two sides I and 2 substantially parallel, and withthese sides provide the major portion of the exterior of the structure;the spars have, furthermore, two side webs 3 and 4 which are shown asbeing, by way of example, arched inwardly whereby their stiffnessagainst buckling is materially increased. The side webs 3 and 4 areperforated with flanged openings l2 which provide access into the sparsduring their fabrication andon their assembly, and further add stiffnessto the side webs. The spars 5 to 8 are spaced from each other so that acavity results between each two confronting side webs 3 and 4, whichcavity is relatively narrow at the corners l0 and II of the spars. but

wide in the interior as thearched webs 3 and 4 bow away from each other.

and II of each two confronting spars, the struts or linear members 9.

.The linear members 9 are either solid or hollow and have recessedflanks closely conforming in profile to the'corners l9 and II, and havea flat surface flush with the exterior surface of the structure cfwhichthey provide a part. The material of which the members 9 are made may beeither extruded or rolled metal for strength and rigidity. or, if thestructure is to serve as a wall, they may be molded of fibroussubstances or of rubber so as to reduce heat transfer, deaden noise andexclude moisture.

In their extreme location at the exterior of the structure the members9, when made of rigid material, provide effective reinforcing means forthe spars 5 to 8 in all conditionsof loading, i. e., endwise, beamwiseand chordwise, and are in turn constrainedagainst buckling by theclamping grip that the stiff corners l0 and H have on them. Moreover,when considered with the joining means as disclosed presently betweenthe spars Ste 8 and the members 9, it will be seen that both the sparsand the members cease to exist as individual and independent elements,and instead, the structure resolves itself mechanically as well asfunctionally into a series of stress girders, each consisting of twolinear members 9 and truss webbing 3 and! between them, while theexterior sides of the spars connect and steady the girders. a Y

A simple manner of assembling the spars 5 to 8 and the linear members 9is represented in Fig. 4, wherein spars 6 and I, representative of anytwo adjacent spars of l, clinch between them the member 9, and areconjoined with this member and Witheach other by means of rivets 35inserted in place through the flangedperforations l2. These perforationscan have any shape, such as round or triangular, and should be alined inconfronting sides but can be overlapped or staggered'in opposite sides,as insides 3 and 4 of spar 6 of Fig. -1, for purposes of providinguniformly easy access for riveting tools for all rivets, particularlythose between successive perforations; I v

Fig. 2 is another embodiment of my invention wherein the shape of thespars !-3 to I6 is different from thatin- Fig; 1, as is the manner ofretaining the linear members in place. The spars l3 to H5 are triangularwith well-defined apices l0 and ll at the exterior surface, and with atruncated apex: l8 away from it. The spars are interposed so thatallupright ones, l3 and I5, jointly form one side of the structurewhilethe complementary inverted spars l4 and I6 form the opposite side; theupright and the in- In this cavity are lodged, at and between therounded corners m verted spars abut one onto each other along a portionof their sides whereby the converging apex portions land I l of each twoupright spars l5 and 13, respectively, in conjunction with the truncatedapex I8 of the inverted spar l4 therebetween jointly define a sheath,socket or cavity in which is confined the linear wedge member H. Theoverhanging apex portions of all inverted spars in conjunction with theblunt apices of the upright spars form similar cavities at the oppositeside of the structure.

The linear members ll are triangular in profiletofill in closely thecavity formed by the spars, and are retained in place by the convergingapex portions l0 and H of these spars, as illustrated on anapproximately full-size scale in Fig; 6. 'In this figure is also shownan exemplary mode of assembling the spars, residing Referring now toFig. 3, the airfoil structiue represented herein has its curvilinearcontour derived from a plurality of substantially triangular cells orspars or elements l9 to 25, each of which constitutes a predeterminedsector in .the airfoil. This structure is a combination of thepreviouslydisclosed two embodiments in that it makes use of triangular spars likethose of Fig. 2, joined together in the manner of those of Fig. 1.Similarly as in Fig. 2, the upright spars I9, 2 I, 23, and

25 provide one side of the structure while the inverted spars 20, 22 and34 provide the opposite side. The spars forming one side as well as theintermediate spars forming the other side are distanced from each other,thereby forming gaps or crevices at the exterior of the structure and aseries of diagonal trusses with spaced double webs in its interior. Atthe extreme point of each truss, in the crevice formed by each two sparsassociated at one side, is lodged the rigid linear member 25; a thismember is employed wherever two diagonal trusses meet at one crevice,

while in the end trusses at the terminal spars l9 and 25 members 9 areused, such as shown in Fig. 4.

A detail view of the linear members 26 and the manner of .confining thembetween the confronting spars 29, 2|, and 22 is illustrated in Fig. 5.In this particular assembly the spars 23 and 22 defining one exteriorsurface are characterized by profiled, such as rounded, corners l9 andII respectively, between which corners is clinched the member 26; theprofile of this .member has recessed sides so as to fill up completelythe crevice between the corners l6 and II and to form a smoothcontinuation of the exterior surface between the respective spars. Thespars 20 and 22 are held together preferably through the instrumentalityof rivets 35 which join the spars at the point where they are closest toeach other, i. e., in their .apices, and at the same penetrate throughthe linear members 26 and clinch them securely between the spars.

The profile of the linear members 26 is furdiate spar 2|. For thispurpose there is secured,

aware? in spaced relation in the apex 21, a number of clinch nuts 34,which nuts are in alinement with and engage the screws 33 that penetratethrough members 26 from the exterior of the structure.

It willnow be seen that the sparsv l9, 2|, 23, and 25, all constitutingone side of the structure, can be joined conveniently, on assembly, intoa unit by means of rivets 35 made accessible through the oppositeflanged holes l2 therein; the spars 20, 22 and 24 constituting the otherside are likewise riveted together into a sub-assembly through thealigned flange holes therein, and then the two opposite andcomplementary rows of spars with the members 26 between them areintermeshed and joined together by means of screws 33 driven in from theexterior. The members 9- are riveted in place through an open end in thestructure or through holes for ailerons, tanks, lights, controls, etc.,in the leading and trailing spars l9 and 25 of the Wing.

I claim:

1. A cellular structure comprising, tubular cellsof sheet materialhaving side walls forming jointly wedge-shaped gaps therebetween, tyingmeans joining said cells through said, side walls thereof, and linearwedges inserted in said gaps, retained therein by said walls andconstrained against dislocation by the clinching action of said Wallsdue to said tyingmeans.

2. A cellular structure composed of individual cells of sheet materialhaving opposing side walls, said side walls of each two associated cellshaving angularly profiled corner portions inwardly of the surface of thestructure, a linear member having angular flanks conforming to. saidcorner portions and being inserted therebetween, and means for joiningeach two associated cells to gether and thereby causing said profiledcorner portions to engage said members bodily and grip them tightlyagainst dislocation under strain.

3. A cellular structure comprising, individual tubular cells of sheetmaterial confronting one another with protruding corners at the surfaceof the structure, and between said corners having side walls recedinginwardly away from each other, linear members having a flared sectionand being inserted between said cells whereby said flared sectionthereof will fit between said receding side walls at and underneath saidprotruding corners, and means for joining said cells together andthereby retaining said members between them and causing said side wallsto clamp them tightly therebetween.

4. A structure comprising, a number of individual tubular elementsarranged in parallel relation and being formed with longitudinal sideportions angularly inclined away from each other from the surface of thestructure inwardly, linear members having a profile conforming to saidangular portions of said tubular elements and being insertedtherebetween, and means for con,- joining said tubular elements andthereby wedging said linear members in place and causing them to abut onsaid angular side portions for their support whensubject to stress.

5. A structure having a dorsal and a ventral side comprising, a numberof individual tubular elements of sheet material arranged side-by-side,said elements having confronting side portions converging toward theexterior surfaces of the structure, linear members having a profile withtapering flanks corresponding to said converging side portions of eachtwo adjacent elements and being inserted therebetween, and means forsecuring said tubular elements together and there- 7 3 y causing, saidlinear member tQ-b wed ed; eh lyhe ween sa d on e porti ns of saidelements, and restrained from dislocation under strain.

6. A structure comprising, a plurality of individuals tubular elementshaving rounded protruding' coir-ners, said elements being arranged inparallel spaced; relation whereby a gap having convergent-divergentsides results between the corners of each twoadjoining elements, anumber oflinear members, said members having a profile narrowed atcenter to conform to said gap,; one member being confined in each gap,and means for-'conjoining said elements into unity and thereby forciblyclamping said members between said rounded corners to prevent theirdislocation under load.-

7.. A structure comprising, a number of individual tubular elementsarranged. in'parallel spaced relation, and having confronting sidesshaped to form constricted longitudinal gaps therebetween at theexterior of the structure, linear rigid members having a constrictedprofile corresponding to said gaps and being lodged apiece thereinwhereby said tubular elements will have a bodily engagement, with saidlinear members against relative motion under strain, and means passingthrough said linear members for conjoining said tubular elements intounity and thereby clamping said linear members firmly therebetween. r

8. A structure comprising, a number of. individual tubular elementsarranged in side-byside relation and having sides forming protrudingshoulders in spaced and opposite longitudinal re'-' lation to each otherat the exterior of the struc-. ture, linear members having hollowflanks, said members being inserted between said shoulders of thetubular elements whereby said elements will have a. constraining holdthereon against failure under load, and means for fastening said tubularelements QSthe fl d thereby gripping, said linear members between saidprotruding shoulders.

9-. A'cellular structure comprising, an exterior shell of sheetmaterial, a series ofdouble-webbed trusses integral with and extendinglengthwise in said shell, said double webs of said trusses forminglate-rally constricted crevices at said shell, linear members havingindented sideslodged in said crevices, and tying means for joining saiddouble; webs of said trusses together and thereby clamping said linearmembers firmly between them. l

10. A cellular structure comprising, tubular cells of' sheet materialhaving side walls, said side walls of each two associated cells having.

convergent-divergent directions from the surface of the structureinwardly, linear members having a double-wedge profile lodged betweensaid walls so that said convergent-divergent portion thereof will have.a' bodily engagement therewith, and means'fo-r tying said wallstogether and thereby clamping said members firmly'therebetween,

' 11. In a structure, an exterior shell substantially'all of sheetmaterial, a series of double webbed trusses extending in said shell andbeing integral therewith, said trusses being inclined one, to eachother; and havingthe webs thereof provided with stiffening means againstbuckling, a number of linear members, one of sai members being confinedat the juncture of each two of; said trusses at said shell and heldfirmly therein by a clinching action of said webs. .12; A structurecomprisin a p urality of ndividual tubular spars, said spars beingsubstantially triangular in shape and being arranged in parallelrelation longitudinally and in inverse and staggered relationtransversely whereby each two alternate spars and one intermediate spartherebetween jointly define a triangular cavity at the exterior of thestructure, a number of linear members having a triangular profile, oneof said members'being inserted in each cavity, and means for conjoiningsaid spars into unity and retaining said members in said cavities.

13. A cellular structure comprising, an exterior shell of sheetmaterial, a series of double-webbed trusses integral with and extendinglengthwise in said shell, said trusses being diagonally inclined towardone another and made to form jointly between the remote webs thereof, atthe surface of the structure, wedge-shaped gaps, linear members havingtapering sides lodged in said gaps and being retained therein by thejoined near webs of said trusses, and means for securing said truss webstogether and thereby clamping said members firmly between them.

14. A cellular structure comprising, a number of triangular tubularcells confronting one another along their sides in inverted'relation,each two alternate cells with one intermediate cell therebetween jointlyforming a crevice with slanted sides at the surface of the structure, alinear filler strip having corresponding slanted sides occupying saidcrevice, and means for securing said cells together through said sidesthereof and thereby constraining said filler strips in place betweensaid slanted sides and said cell therebetween.

15. A structure comprising, a plurality of individual tubular elementshaving side webs and chord webs meeting in a number of apices, said sidewebs confronting one another and having diverging directions from saidapices inwardly, two linear members confined between each two elementsat said chord Webs thereof, said members having a profile conforming tosaid apices and said converging sides of said elements and forming asmooth portion of the exterior between said chord webs thereof, andmeansfor conjoining said elements and thereby locking said members betweensaid side webs;

16. A structure comprising, a plurality of individual tubularsparshaving each two side webs and two chord webs meeting in four roundedapices, said spars defining the major portion of the exterior of thestructure with said chord webs thereof and confronting one another at arelatively small distance along said side webs thereof, said side websof each spar being indented inwardly between said rounded apices andbeing perforated with flanged holes, a number of linear members havingconcave sides, one of said members being confined between said cornersof each two confronting spars and between said indented walls and madeto provide the portion of the exterior of the structure therebetween,and means in the interior of the structure forconjoining said spars intounity and thereby clamping said members therebetween.

17.'A structure comprising, a number of individual tubular elementsarranged in side-byside spaced relation and having convex portions inopposite longitudinal relation to each other, linear members havingconcave flanks, said members being fitted between said convex portionsof said tubular elements whereby said elements will have a constraininghold thereon against failure under load, and means for fastening saidtubular elements together "and-thereby clinching said linear memberstherebetween. V 4

18. Astructu're" comprising, a plurality of individual tubular elements,a number of triangular linear members, and means for fastening saidelements together in parallel relation, said tubular elements havingsides formed so that at least each two of them jointly define one tIi:angular-cavity having one apexat the exterior of'the surface and theother two apices inwardly thereof, one ofsaid linear members beingconfined in'each cavity and forcibly constrained by said elementstherein against dislocation under strain.

19, A cellular structure comprising, a number of tubular cells havingcertain corners thereof protruding and others truncated, each two ofsaid cells approaching each other at the exterior surface of thestructure with said protruding corners thereof and including onetruncated corner of a third cell therebetween to form a triangularsheath, a triangular linear member conforming to said sheath and beingthrust therein, and means for tying said cells together and'therebyexerting a tight hold on said member between said corners thereof.

20-. A cellular structure comprising, tubular cells of sheet materialmeeting one another along the surface of the structure and having sidessloping in opposite directions inwardly from said surface, other cellsbetween said first named cells having sides conforming to said slopingsides thereof and having truncated apices therebetween, triangularlinear members in the space between said'sloping sides of said firstcells and said truncated apices of said second cells, and means fortying said first cells together with said second cells through saidsloping sides thereof and thereby wedging said triangular membersbetween 'said'sides and apices. v

21. A cellular structure comprising, a row of tubular triangular cellshaving contacting corners at the exterior of the structure andtruncated'corners in the interior thereof, another row of like cellsinverse to and alternating with said first row and having the sidesthereof confront said first row whereby a triangular gap results betweenthe contacting corners of two cells in one row and the truncated cornerof one cell of the other row, triangular linear members inserted in saidtriangular gaps, and means for tying said two rows of cells together andthereby constraining said linear members between said contacting andsaid truncated corners of said cells.

22. A structure comprising, a plurality of individual tubular spars,said spars being substantially triangular in shape with at least twowelldefined apices and being disposed inversely to each other in spacedrelation whereby alternate spars will confront intermediate spars alongtheir sides'at a relatively small distance, said well-defined apices ofeach two alternate spars and the intermediate spar therebetween jointlydefining a crevice at the exterior of the structure; a linear memberinserted in each crevice between said well-defined apices therein toprovide spacing means for said spars and complemental' means totheexterior of the structure between said spars, and means for conjoiningsaid spars into unity and thereby clinching said members therebetween.

23. A cellular structure comprising, a number of tubular-cells havingprotruding corners, each three of said-cells approaching one another atthe exterior surface of the structure unth said corners thereof inspaced relation and forming a constricted crevice therebetween, a linearmember having three sides thereof conforming to said corners of saidcells, said member being inserted in said crevice with said cornersfitting in and against said three sides of said member, and means fortying said cells together through said corners thereof and through thebody of said member therebetween.

24. Acellular structure comprising, a row of tubular triangular cellshaving alined corners in spaced relation at the exterior of thestructure and their third corners away therefrom, another row of likecells inverse to and alternating with said first row and having thesides thereof confront said first row whereby a constricted gap resultsbetween said spaced corners of each two cells in one row and the thirdcorner of a cell from said second row therebetween, linear membershaving tapered sides conforming to said constricted gaps and beinginserted therein, and means for tying said cells in, each row with oneanother through said linear members therebetween, and means for tyingsaid first row of cells with said second row through said linear memberstherebetween.

25. A cellular structure comprising, a row of triangular tubular cellshaving spaced corners from each other at the surface of the structure,linear members having recessed sides and having a groove betweenthem inthe interior of the structure, said members fitting between said spacedcorners of said cells and being bodily engaged thereby insaid recessedsides thereof, tying means extending through said linear members forjoining said cells together in said corners thereof; another row of likecells comple menting said first row in inverted relation, said secondrow having corners fitting into said grooves in said linear members, andtying means extending from the surface of the structure into engagementwith said grooves in said linear members. 7

g 26. In a cellular structure, a row of tubular cells having slopingsides and having spaced corners from one another at the surface of thestructure, linear members fitting between said spaced corners, and meansfor tying said cells and said linear members together; another row ofcells having sloping sides and complementing said first row in invertedrelation, said second row of cells having corners protruding betweeneach two cells of said first row toward said linear memberstherebetween, nuts located in said protruding 'corners'of said cells,and screw means projecting through said linear members and engaging saidnuts and thereby pulling said cells of said second row into placebetween said cells of said first row.

1 JOHN PAVLECKA.

